The MEPS-IC is an annual survey that collects
information about employer-sponsored health insurance offerings
in the United States. Collection began with the 1996 survey year.

A nationally representative sample of employers, developed
from Census Bureau list frames for the private sector and State
and local governments, is the basis for the survey and the
posted tables of estimates.

Beginning with the 2008 survey reference year, the MEPS-IC
survey’s collection year is the same as the calendar
year (current collection). Prior to 2008, collection for a
survey reference year was done in the following calendar year
(retrospective collection) – i.e., 2005 survey year data
were collected in calendar year 2006. The switch to calendar
year collection allows the survey to release private sector
estimates for a given survey year a full 12 months earlier
than was possible for the pre-2008 surveys. For example, 2008
estimates were released in July 2009; without the switch, they
would have been released in July 2010. State and local governments’ estimates
are released several months after the private sector estimates for the same survey year.
(Due to the change to current collection, 2007 estimates are
not available.)

The following types of national estimates are available from
the MEPS-IC private-sector tables posted on the survey’s website:

Establishment based (for example, the percent of establishments that offer
health insurance)

Employee based (for example, the percent
of employees that enroll in health insurance plans)

Premiums and employee contributions
for enrollees, including averages and percentile distributions

Deductibles and copayments for enrollees

These estimates are defined for firm size, industry, and other establishment characteristics.

Government tables have estimates similar to those for the private sector, broken out for State governments and local governments by size.

See the Glossary
for definitions of terms used in the survey questionnaires and tables of estimates.

(NOTE: Collection for the MEPS-IC Household Link Sample,
a sample of employers of persons who responded to the
MEPS Household Component (MEPS-HC) survey, was suspended in 2002.)

In addition
to producing national estimates, the sample allocation
and design of the MEPS-IC sample also supports reliable
private sector State-level estimates of the same type noted above.

Since 2003, there has been a sufficient MEPS-IC sample
each year to support State-level estimates in all 50
States and the District of Columbia. (For survey purposes,
the District of Columbia is treated as a State.) When
the survey began, cost constraints prevented the fielding
of a sufficiently large sample to support State estimates
for all States every year. In 1996, estimates were made
for the 40 most populous States. From 1997 through 2002,
the MEPS-IC rotated the samples in the 20 least populated
States to insure that every State received an adequate
sample size to make State-level estimates at least once
every four years. The 21 States that were not allocated
sufficient sample for estimates each year during the
years 1996 - 2002 are listed in the following table.
An "X" indicates the year(s) for which State
estimates are available for that State. A blank indicates
that estimates are not available for that State in that
year. The State rotation schedule was modified in 2001
to reflect changes in State population rankings based on the 2000 Census.

States with smaller populations for which MEPS-IC estimates are not available each year 1996–2002

State

1996

1997

1998

1999

2000

2001

2002

Alaska

X

X

Arkansas

X

X

X

X

X

X

Delaware

X

X*

X

District of Columbia

X

X

Hawaii

X

X

X

X

X*

Idaho

X

X

Kansas

X

X

X

X

X

**

X

Maine

X

X

X

X

X*

Mississippi

X

X

X

X

X

X

Montana

X

X*

Nebraska

X

X

X

X

X

Nevada

X

X

X

X

X

New Hampshire

X

X

**

X

New Mexico

X

X

X

X

North Dakota

X

Rhode Island

X

X

X

South Dakota

X

**

Utah

X

X

X

X

X

X

Vermont

X

X*

West Virginia

X

X

X

X

Wyoming

X

X

Note: An X indicates that State-level estimates are available for that
year; a blank indicates that there are no estimates for that year.* States received an additional sample that supported a full set of State estimates not otherwise possible. ** States received an additional sample that supported estimates for smaller firms only.

Federal
agencies, State governments, and non-profit organizations
have occasionally provided additional funding to increase
the MEPS-IC samples in selected States. The two most
common reasons for funding larger State samples are
1) to improve the accuracy of the State estimates for
that year or 2) to provide sufficient sample for production
of State estimates in a year where no estimates would
have been produced otherwise. In the table below, States
that received increased samples are listed by year.
In 2001 and 2002, the increased samples resulted in
additional States for which estimates could be produced.
These additional estimates are provided on the MEPS-IC
Web site to all data users.

* States received an additional sample that
supported a full set of State estimates not otherwise possible.** States received an additional sample that
supported estimates for smaller firms only.*** The U.S. Virgin Islands received a special
sample to support a full set of estimates. These data are not included
in the calculation of totals for the United States.

Starting with the 2002 data collection, the
sample allocation and design of the MEPS-IC sample also supports
a limited set of reliable private sector metropolitan-level estimates
of the following:

The percent of establishments that offer health insurance

The percent of employees that enroll in health insurance
plans, are eligible to enroll, and enroll when they are eligible

Average premiums and employee contributions for those enrolled
in employer-sponsored health insurance plans

Estimates are provided for the 20 largest metro areas nationwide and for at least
one metro area within each state. The metropolitan statistical areas with a sufficient sample
size to support reliable estimates with the MEPS-IC are geographically defined in the
following two tables:

The MEPS-IC private-sector sample is selected and collection takes place
at the establishment (unit) level. An establishment is generally a single physical
location; a firm can consist of just a single establishment or multiple establishments. The sampling unit for governments is the parent agency and any dependent agencies. In the following discussion, the term establishment is used to refer to both the private-sector and state and local government sampling unit.

For all sample units except 1) State governments, 2) very large local governments,
and 3) those in complex multi-unit (those with nine or more establishments
in the sample) private sector firms, each sample unit is initially prescreened
by telephone. The purpose of this screening is to:

Determine whether or not health insurance is offered to employees at each establishment.

Obtain the name, title, and address of an appropriate person in each establishment
to whom a MEPS-IC questionnaire will be mailed (for establishments offering health insurance).

Identify any establishment that no longer exists, has closed, or has merged with others.

If the employer did not offer health insurance, a brief
set of questions about establishment characteristics are asked
during the screening process and the case is considered
a complete response. This provides an inexpensive method to collect the
necessary data from the large number of employers who did not
offer health insurance, while minimizing the collection burden on those generally small employers.

If the employer did offer health insurance, several short questions
are asked and the employer is later mailed a MEPS-IC questionnaire
to obtain the remaining needed information. All establishments not reached during the screening
process are also mailed questionnaires. Establishments are given the option of completing the mail
questionnaire or responding on-line. If an establishment fails to respond to the initial
mail questionnaire, a follow-up mailing is sent a few weeks later.
Establishments that also fail to respond to the second mailing and do not respond on-line
are contacted by telephone and the survey is conducted using computer-assisted telephone interviewing
(CATI) technology.

For the purpose of this survey, establishments indicating
that they offered health insurance to their employees must answer key information on their health
insurance offerings to be considered full respondents. Callbacks are made to respondents not providing
all of the key information in order to complete their questionnaires. Respondents that do not provide
this key information, but are known to offer insurance, are considered partial respondents.
Establishments that were not prescreened, did not return the mail questionnaires and did not respond
to follow-up phone calls are classified as non-respondents. For this group, the availability of health
insurance for employees at the establishment is unknown.

Data for large governments and very large private-sector firms are collected using specialized
staff and forms. This is done to make the collection process simple and flexible and to reduce the
burden as much as possible for these important respondents. Sometimes multiple telephone contacts and personal
visits are needed to collect these data. For some of these collections, survey staff abstract data directly
from company records and plan brochures if the firm insists on such methods.

In sample surveys like the MEPS-IC, non-certainty
sample establishments represent not only themselves but also other similar
establishments in the survey population. Therefore, in order to produce
the survey estimates and standard errors presented in the MEPS-IC tables,
weights must be created for all responding establishments. A brief description
of this process is provided here. During the sample design and selection
process, each establishment on the frame is given a probability of selection
that is dependent on its stratum. These probabilities vary among establishments
and assure that the sample sizes in each stratum are equal to that required
by the allocation scheme. The inverse of this probability of selection
is the establishment’s base weight. The use of the base weight and
the formula

provides an unbiased estimate of a total T, if there is no non-response.

Because there is non-response, respondents’ weights are adjusted to account
for non-response so that these weights, when used with responding establishment
data, will reduce the bias attributable to survey non-response. To accomplish
this, the sample is divided into cells similar to the original sampling strata
and the weights for each respondent in a specific cell are adjusted upward
by the same percentage. The sum of the adjusted weights for respondents in
these cells is equal to the sum of the base weights for all in-scope sampled establishments
in the cell. Because it is assumed that the expected value of all responding
establishments in each individual cell defined is equal to that of all the
eligible respondents, use of the adjusted weights with respondents should produce
the desired unbiased estimates of totals. Additional details on the enrollment
and expenditure estimation process are available in
MEPS
Methodology Report No. 14, June 2003.

After adjustment for non-response, weights are post-stratified (Madow, Olkin,
and Rubin, 1983.) using the frame of establishments in business during the last
quarter of the year for which estimates would be made to produce control totals.
For detailed information concerning construction of weights, see
MEPS Methodology
Report No. 28, October 2013.

Although railroads are included in the sample, the six largest railroads are not included
in the MEPS-IC tables (except in the Series IV National totals). Employment for these railroads cannot be broken
down by State so their inclusion would distort results for States in which the
headquarters of these railroads are located.

» Reliability of Estimates

For each table of estimates, a corresponding table of standard errors is provided.
Beginning with 2014 data, standard errors are computed using the Taylor series linearization method
- a widely used method of variance estimation for sample survey estimates.
For details about the Taylor series method of variance estimation see Lohr (2009);
Särndal, Swensson, and Wretman (1992); Lee, Forthoffer, and Lorimor (1989); and Wolter (1985).
The computational details of the Taylor series variance estimation method for all different types of estimates
in tables can be found in SAS Stat User's Guide (2012) or SUDAAN Technical Manual (1996).

As an example, under the Taylor series method, the variance (square of standard error) of
an estimator of total,

can be expressed as:

with

where, h represents the sampling stratum, nh is the sample size after nonresponse in stratum h, xhi is the
value of a survey variable for establishment i in stratum h, whi is the corresponding final nonresponse-adjusted
sampling weight for the same establishment, and

is the finite population correction (FPC) factor. Initially the FPC factor was not included in the Taylor Series variance
estimation formula but starting in 2017 it was incorporated to improve estimation by accounting for sampling rates
(Chowdhury et al., 2018).

Prior to 2014, standard errors for MEPS-IC estimates were produced using the method of random groups
(Wolter, 1985; Skinner, Holt and Smith, 1989). During the sample selection process, each selected establishment
was assigned a number from 0-9 sequentially to form 10 random groups. Considering each of these groups as a
subsample similar to the full sample and assigning subsample weights that are 10 times the weights of the full
sample, ten subsample estimates, θi , i = 1, 2, ...10 were made in addition to the full
sample estimate, θ. The variance was then calculated as

The MEPS-IC tables are numbered in a hierarchical structure that facilitates
locating estimates, helps clarify specifically what the estimates are measuring,
and provides a mechanism for calculating count estimates for tables where percentages
are provided. The numbering structure also serves as the framework for the MEPSnet/IC
interactive search tool, which is available on the survey website.

The first level of the table numbering system is by the following categories
and by year:

Private-sector data by firm size and selected characteristics for the U.S.

Private-sector data by firm size and State

Public-sector data by government type, government size, and census division

National totals for enrollees and cost of health insurance coverage for the private and public sectors

Private-sector data by industry groupings and State

Private-sector data by ownership type and age of firm and State

Private-sector data by proportion of employees who are full-time or low-wage and State

Private-sector data by average wage quartiles and State

Private-sector data by Metro areas

Private sector data of percentile distributions of premiums, employee contributions, and employer costs and State

Civilian data by private and state/local government sectors and census divisions

Within each of these categories (excluding Tables IV, IX, and X), tables
are subsequently grouped by:

Establishment-level tables

Employee-level tables

Premiums, employee contributions, and enrollment tables for single coverage plans

Premiums, employee contributions, and enrollment tables for family coverage plans

Note: Denominators are available only for tables that provide percentage estimates
of counts. No “G” tables have percentage estimates
of counts. Also, the “X” series of percentile distributions has
no percentage estimates of counts.

Many of the MEPS-IC tables contain percent estimates instead
of count estimates. For instance, Table I.B.2 gives the percent of employees
who work in establishments that offer health insurance. Table I.B.2.a gives
the percent of employees who work at establishments that offer health insurance
and who are eligible for health insurance. For most tables of percents, a count
of the number of employees or establishments in any cell in the table can be
calculated using data, for that cell, from the current table and one or more
tables containing the denominator(s) for that cell.

To produce count estimates, multiply the cell values from the
selected table and all of the denominators for that cell. For example,
to estimate the total number of establishments that offer health insurance, use the percentage of these establishments in Table I.A.2 and determine
from Figure 1 above that Table I.A.1 contains the value in the
denominator of this percentage.

Thus, the estimated total number of establishments that offer health insurance
in 2013 is: .499(percents must be converted to decimals) x 7,009,707 = 3,497,844.
The first number (.499) is from Table I.A.2 and the second (7,009,707) is from
Table I.A.
An approximate standard error for this count estimate can be computed using
this formula:

where Est(1) and Est(2) are the estimates from the two tables and Err(1) and Err(2) are the standard errors for those estimates.

For some tables, a hierarchical structure exists so more
than two tables are needed to derive an approximate count. For example, look
at Table I.B.2.a, the percent of employees eligible for health insurance. Table
I.B.2 is listed as its denominator for Table I.B.2.a and Table I.B.1 is the
denominator for Table I.B.2. The values from all three tables, I.B.1, I.B.2,
and I.B.2.a must be used to derive an estimate of the count. Thus, the estimated
total number of employees eligible for health insurance in 2013 is .778 x .849
x 113,947,523 = 75,264,846, with the three values coming from Tables I.B.2.a,
I.B.2, and I.B.1 respectively. Basically, one must multiply by a series of
denominators until one reaches a table with numbers instead of percents (the
shaded areas of the Table 1 on the previous page). The standard error for this
count estimate (674,645) can be computed by using a logical expansion of the
standard error formula provided above.

Each year the MEPS-IC survey undergoes a number of changes in an effort to
improve the existing survey while maintaining continuity from one year to the
next. Listed below are the most significant changes that occurred in each year.
In addition to the changes listed here, there were also changes to the wording
and question order based on feedback from survey respondents.

Survey year

Major changes

1996

Initial survey year.

1997

Establishment Form

Dropped questions on retiree health insurance at the establishment-level and revised for collection at the company-level.

Company Form

Added company-level forms (15 and 15S) for cases where data collection at the establishment-level was not feasible.

Methodology

A rotation schedule to produce estimates for smaller States was introduced.

Dropped sample of Self Employed with No Employees sample.

Tables

Added a significant number of tables, introduced a new table-numbering system, and revised 1996 tables (using improved imputation and weighting methods) were reissued. The 1996 tables posted on the MEPS-IC Web site reflect these changes.

1998

Establishment Form

Added follow-up questionnaire 10M for interviews of multi-establishment respondents where the Computer Assisted Telephone Instrument was not functioning.

Plan Form

Removed the "first" plan-level questionnaire from the establishment and government questionnaires.

No MEPS-IC data are available for 2007 due to the transition from retrospective to current data collection.

2008

Establishment Form

Revised question on cost of optional insurance coverage and changed reference from annual to monthly.

Methodology

Changed data collection from retrospective (calendar year following survey year) to current (calendar year same as survey year). Current collection makes private sector estimates for the survey year available 12 months earlier and government estimates available eight months earlier, compared to retrospective collection.

2009

Establishment Form

Added questions about limits on covering the spouse of an enrollee and about incentives provided to employees if they did not elect to take coverage.

2010

Tables

Added a new set of tables that provide comparable estimates at the Census Division level for the private-sector, State and local governments, and a combination of both.

2011

No changes.

2012

Establishment Form

Added question on number of employees earning above a specific hourly wage (to be updated annually).

Added question for small employers only on whether Small Business Health Care Tax Credit will be claimed.

Chowdhury, S., Kashihara, D., and Thompson, M. (2018). Incorporating a Finite Population Correction into the Variance
Estimation of a National Business Survey. Proceedings of the Federal Committee on Statistical Methods (FCSM), 2018 Annual Conference.